Invert broken check of panic string in if_linkstate().

original bug report from syzkaller
Reported-by: syzbot+d19060a65721eb432a72@syzkaller.appspotmail.com
broken fix found by Hrvoje Popovski
hint to the problem and OK deraadt@

diff --git a/sys/net/if.c b/sys/net/if.c
index 6677cf0..9b97125 100644 (file)
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if.c,v 1.717 2024/02/05 18:27:47 mvs Exp $    */
+/*     $OpenBSD: if.c,v 1.718 2024/02/06 00:18:53 bluhm Exp $  */
 /*     $NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $  */
 
 /*
@@ -1788,7 +1788,7 @@ if_linkstate(struct ifnet *ifp)
 {
        NET_ASSERT_LOCKED();
 
-       if (panicstr != NULL) {
+       if (panicstr == NULL) {
                rtm_ifchg(ifp);
                rt_if_track(ifp);
        }